We understand bats are beneficial critters, but we have been struggling for the past couple years with them coming into a customer’s attic. What can we do to prevent them from coming into our home?
It is illegal to kill bats in most states because they are protected. Young bats are born between April through August, which can make any type of removal and exclusion work difficult especially if there are young that are not ready to leave the attic. The best time for bat proofing is during September through March after the young bats have learned to fly.
It is important to first focus your efforts on safely removing the bats by constructing a one-way exclusion net around the entry points that are used by the bats. Bats are very small, and only need about 3/8 inch gap to slip through.
Once the bats are out, physical exclusion work can begin, which often takes the form of replacing pieces of siding or flashing, sealing gaps with caulk or mortar (ie: where the chimney attaches to the house itself), and securing a mesh screen behind attic vents and soffits. Exclusion work should be done on the inside and outside of a structure. Bats follow air currents, so if there is any light or air penetrating into the attic space between the wood frames, windows, or vents, use those as clues to potential entry points that must be sealed.